CELIAC DISEASE COMPREHENSIVE CASCADE
Marquette General Health System
General Info
HLAB/HOL Code |
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CELCC |
MGH LIS Test No |
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4344 |
Schedule |
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Varies |
Testing Time |
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7 - 14 Days |
Testing Lab |
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Mayo Labs |
QORR Test Code |
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CELCC |
Specimen Info
Type |
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Blood and serum are required
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Volume |
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Temperature |
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Blood- Ambient; Serum - Refrigerated |
Preservative |
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Collection Info |
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Blood and serum are required for this test.
Blood
Draw blood in a yellow-top (ACD [solution B]) tube(s), and send
7 mL of ACD (solution B) whole blood. Do not transfer blood to other
containers. Forward promptly at ambient temperature only.
Serum
Draw blood in a plain, red-top tube(s) or a serum gel tube(s). Spin
down and send 2 mL of serum refrigerated. |
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Specimen Acceptability
Methods
Immunoglobulin A (IgA):
Total IgA levels are measured by immunonephelometry. Rabbit
antisera that specifically recognizes human IgA is added to the
patient sample. Immune complexes form between the human IgA
and the rabbit immunoglobulins; the immune complexes scatter
light that is passed through the sample. The intensity of the
scattered light is related to the amount of human IgA in the sample.
The concentration of IgA in the sample is calculated from a
multipoint calibration curve. (Behring Nephelometer II Operations
Instruction Manual. Dade Behring, Inc. Newark, DE 19714)
HLA-DQ Typing:
The INNO-LiPA HLA typing tests are based on the reverse
hybridization principle. Amplified biotinylated DNA is chemically
denatured; separated strands are hybridized to specific
oligonucleotide probes immobilized as parallel lines on
membrane-based strips. After a stringent wash, alkaline
phosphatase-conjugated streptavidin is added, which binds to
any biotinylated hybrid. Incubation with a chromogenic substrate
results in a purple/brown precipitate. The reaction is stopped by
a wash step and the reactivity pattern of the probes is recorded.
The strip is then scanned into a computer, which analyzes the
positive bands and interprets the results. (Immunogenetics Inc.
2580 Westside Parkway, Suite 400, Alpharetta, GA, 30004)
Tissue Transglutaminase (tTG) Ab:
IgA and IgG antibodies to tTG are detected by enzyme-linked
immunosorbent assay (ELISA). Recombinant human tTG antigen
expressed in Escherichia coli is adsorbed to wells of a microtiter
plate under conditions that preserve the native state of the antigen.
Diluted patient sera are added to the microtiter plate wells under
conditions that allow binding of the antibodies to the tTG antigen.
Unbound sample constituents are washed away and horseradish
peroxidase (HRP)-labeled antihuman IgA or IgG antibody
conjugate is added to each well. After a second incubation,
unbound HRP-label is removed and bound conjugate is detected
by adding tetramethylbenzidine (TMB) chromogenic substrate.
After a final incubation, colored product is measured
spectrophotometrically; the absorbance of the patient sample is
compared to the positive calibrator. The absorbance is directly
proportional to the level of IgA or IgG antibodies to tTG, which is
expressed in arbitrary units(QUANTA Lite R h-tTG IgA and IgG.
Inova Diagnostics, Inc. San Diego, CA, 92131)
Gliadin (Deamidated) Ab, IgA/IgG:
IgA and IgG antibodies to deamidated gliadin peptides are
detected by enzyme-linked immunosorbent assay (ELISA).
Purified peptides are adsorbed to wells of a microtiter plate under
conditions that preserve the native state of the antigen. Diluted
patient sera are added to the microtiter plate wells under
conditions that allow binding of the antibodies to the deamidated
gliadin peptides. Unbound sample constituents are washed away
and HRP-labeled antihuman IgA or IgG antibody conjugate is
added to each well. After a second incubation, unbound HRP-
label is removed and bound conjugate is detected by adding
tetramethylbenzidine (TMB) chromogenic substrate. After a final
incubation, colored product is measured spectrophotometrically;
the absorbance of the patient sample is compared to the positive
calibrator. The absorbance is directly proportional to the level of
IgA or IgG antibodies to deamidated gliadin peptides, which is
expressed in arbitrary units. (QUANTA Lite Gliadin IgA II and
IgG II. INOVA Diagnostics, Inc. San Diego, CA, 92131)
Endomysial (EMA) Ab, IgA:
IgA endomysial antibodies are detected by indirect
immunofluorescence assay (IFA). Frozen sections of rhesus
monkey esophagus substrate are overlaid with dilutions of
patient sera and incubated. After washing, the slides are overlaid
with fluorescein-conjugated IgA antisera and incubated. After a
final washing, the slides are analyzed through fluorescence
microscopy. (Chorzelski TP, Beutner EH, Sulet J, et al: IgA
anti-endomysium antibody: A new immunological marker of
dermatitis herpetiformis and coeliac disease. Br J Dermatol
1984;111:395-402)
Clinical Utilities
Evaluating patients suspected of having celiac disease, including
patients with compatible symptoms, patients with atypical
symptoms, and individuals at increased risk (family history,
previous diagnosis with associated disease)
CPT Codes
82784-IgA
86816-HLA-DQ typing
83516-Deaminated gliadin IgA (if appropriate)
83516-Deaminated gliadin IgG (if appropriate)
83516-tTG IgA (if appropriate)
83516-tTG IgG (if appropriate)
86256-Endomysial antibodies (if appropriate)
The following tests may be added per the testing algorithm:
Mayo #82587 "Tissue Transglutaminase (tTG) IgA
Antibodies, Serum"
Mayo #9360 "Endomysial Antibodies (IgA), Serum"
Mayo #89029 "Gliadin (Deamidated) Antibody, IgA, Serum"
Mayo #83660 "Tissue Transglutaminase (tTG) Antibody,
IgG, Serum"
Mayo #89030 "Gliadin (Deamidated) Antibody, IgG, Serum"
The CPT codes provided are based on AMA guidelines
and are for informational purposes only. CPT coding is the
sole responsibility of the billing party. Please direct any questions
regarding coding to the payer being billed.
Reference Range
An Interpretive Report will be provided.
Component Information
Collection Notes
Additional Comments
Questions or Comments email support@mgh.org
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